As a beginner many get confused about stretching paper, what does it involve and why would you need to stretch paper?
Why Stretch Paper?
Stretching paper gives a perfectly flat surface on which to work and your paper won’t buckle when you use watercolour or other water-based media.
Paper is usually stretched for watercolour work but it is useful for any media as papers of less than 250gsm usually buckle. Paper doesn’t always buckle it depends on the amount of water you use and how much the paper has to absorb and the type of paper. It is always best to stretch paper to ensure a non-buckled perfectly flat surface.
Very thick watercolour is good at not buckling and many get away without stretching it. I think it is wise to stretch all paper however if you are using watercolour and other very watery media.
What Do I Need to Stretch Paper?
A piece of wood board, brown gum tape, a good sponge and a scalpel knife.
Soak your paper in a shallow bath and leave it for at least 30 minutes.
Drain off the paper and place it on the board. Using your sponge soak up any excess water and flatten onto the board.
Cut the gum tape into lengths long enough to cover the board around the edges. Now use your sponge to wet the gum tape and tape down the paper.
Tip: Make sure you stick the gum tape around the corners of the board
The paper and board must be left now to dry flat somewhere. The board must be completely flat not vertical, so leave it to dry on a table or something flat. Once completely dry you can work on your paper.
Once you have finished painting your paper will dry completely flat! You then need to carefully cut out your painting from the board using a scalpel knife.
Also see What is Watercolour?